The present application is based upon, and claims priority to, Japanese Patent Application Nos. 2001-325819, filed Oct. 24, 2001, 2001-344174, filed Nov. 9, 2001, 2001-339848, filed Nov. 5, 2001, and 2001-339849, filed Nov. 5, 2001, the entire contents of all of which are hereby incorporated by reference.
1. Field of the Invention
The present invention relates to a jet propulsion unit for a watercraft, and more particularly, to a reverse thrust arrangement for a small watercraft.
2. Description of the Related Art
Personal watercraft have become very popular in recent years. This type of watercraft is quite sporting in nature and carries a rider and possibly one or more passengers. A relatively small hull of the watercraft commonly defines a rider""s area above an engine compartment. An internal combustion engine is commonly used to power a jet propulsion unit which propels the watercraft. The engine lies within the engine compartment in front of a tunnel formed on the underside of the watercraft hull. The jet propulsion unit is located within the tunnel and is driven by an output shaft of the engine. An impeller shaft of the jet propulsion unit extends forward, through a wall of the hull tunnel, and is coupled to the engine output shaft. In this manner, the engine drives the jet propulsion unit.
The jet propulsion unit conventionally includes an impeller housing in which an impeller is contained. The impeller, which is driven by the engine through the impeller shaft, draws water through a water inlet and forces it through a discharge nozzle to propel the watercraft. A steering nozzle usually is mounted on the discharge nozzle for pivotal movement about a vertical axis. Pivotal movement of the steering nozzle about the vertical steering axis alters a discharge direction of the water jet to steer the watercraft.
Many personal watercraft also include a water reverse thrust deflector or xe2x80x9creverse bucketxe2x80x9d for redirecting the jet forwardly, thereby producing a reverse thrust. The reverse thrust deflector is usually supported about the end of the jet propulsion unit to move pivotally between a raised position, in which the deflector does not affect the water jet issuing from the steering nozzle, and a fully lowered position, in which the deflector cooperates with the steering nozzle and redirects water issuing from the jet propulsion unit forwardly to achieve the reverse thrust.
The position of the reverse thrust deflector is usually controlled through an actuator accessible to the operator of the watercraft. A control arrangement couples the reverse thrust deflector for movement with the actuator. Common control arrangements include a mechanical cable, or bowden-wire, or an electronic arrangement. A mechanical arrangement typically requires a large amount of force to move the actuator and thus move the reverse thrust deflector between the raised and the fully lowered position. Because the operator must also control the throttle at the same time, such an arrangement makes the operation of the reverse mechanism more difficult. An electronic arrangement reduces the effort required by the operator, but increases the manufacturing cost and reduces reliability of the watercraft.
A need therefore exists for a watercraft reverse thrust arrangement that provides for precise steering movements during reversal of the watercraft. Preferably, such an arrangement reduces the effort required by the operator to move the reverse thrust deflector between the raised position and the fully lowered position and is relatively inexpensive to manufacture.
In accordance with one aspect of one embodiment of an invention disclosed herein, a watercraft comprises a hull, the hull defining an engine compartment, and an engine disposed within the engine compartment. A jet propulsion unit is driven by the engine, the jet propulsion unit comprising a discharge nozzle configured to direct a water jet in a generally rearward direction. A water diverter bucket assembly is mounted near the discharge nozzle and movable between an opened position and a closed position wherein the bucket assembly at least partially redirects the water jet. A control assembly is provided for moving the bucket assembly between the opened and closed position. The control assembly comprises an electric motor, an actuator configured to operate the electric motor, and a cable clutch mechanism. The cable clutch mechanism comprises at least one spool driven by the electric motor. At least one operation cable is wound around the at least one spool and includes a first end and a second end. The first end is coupled to the actuator and the second end is coupled to the bucket assembly. The movement of the actuator moves the first end of the operation cable and activates the electric motor. The at least one operation cable frictionally engages the spool to move the second end of the operation cable and thereby move the bucket assembly toward one of the open and closed positions.
In accordance with another aspect of an embodiment of an invention disclosed herein, a watercraft comprises a hull and an engine supported by the hull. A jet propulsion unit is driven by the engine. The jet propulsion unit comprises a discharge nozzle configured to direct a water jet in a generally rearward direction. A water diverter bucket assembly is mounted near the discharge nozzle and is movable between an open position and a closed position in which the bucket assembly at least partially redirects the water jet. A control assembly is configured to move the bucket assembly between the first and second positions. The control assembly comprises an electric motor, an actuator configured to operate the electric motor, and a cable clutch mechanism. The cable clutch mechanism comprises a first spool and a second spool driven by the electric motor. The first spool is driven in a first direction and the second spool is driven in a second direction opposite the first direction. A first operation cable is wound around the first spool and includes a first end and a second end. A second operation cable is wound around the second spool and includes a first end and a second end. An input arm is coupled to the actuator, and an output arm is coupled to the bucket assembly. The first ends of the first and second operation cables are connected to the input arm and the second ends of the first and second operation cables are connected to the output arm. Movement of the input arm in a first direction causes the first operation cable to frictionally engage the first spool and move the output arm in a first direction thereby moving the deflector assembly toward the open position. Movement of the input arm in a second direction causes the second operation cable to frictionally engage the second spool and move the output arm in a second direction thereby moving the deflector assembly toward the closed position.
In accordance with a further aspect of an embodiment of an invention disclosed herein, a watercraft comprises a hull, an engine supported by the hull, the engine comprising a power output control device configured to influence a power output of the engine, a jet propulsion unit driven by the engine. The jet propulsion unit comprises a discharge nozzle configured to direct a stream of pressurized water in a generally rearward direction. A water diverter bucket assembly is mounted near the discharge nozzle and movable between an open position and a closed position in which the water diverter bucket assembly at least partially redirects the stream of pressurized water. A reverse cable is configured to move the deflector assembly between the open position and the closed position. A secondary control actuator is coupled to the reverse cable and is connected to the power output control device. The secondary control actuator is configured to adjust the power output control device to increase the power output of the engine after the water diverter bucket assembly reaches the second position.
In accordance with yet another aspect of an embodiment of an invention disclosed herein, a watercraft comprises a hull and an engine is supported by the hull. A jet propulsion unit is driven by the engine. The jet propulsion unit comprises a discharge nozzle configured to direct a water jet in a generally rearward direction. The hull includes at least one inlet, at least one outlet, and at least one secondary flow passage connecting the at least one inlet to the at least one outlet. A water diverter bucket assembly is mounted near the discharge nozzle and is movable between a first position and a second position in which the bucket assembly redirects at least a portion of the water jet toward the at least one inlet. At least one lid member is associated with the at least one outlet and movable between an open position and a closed position.
In accordance with an additional aspect of an embodiment of an invention disclosed herein, a watercraft comprises a hull. An engine is supported by the hull. A jet propulsion unit is driven by the engine. The jet propulsion unit comprises a discharge nozzle configured to direct a water jet in a generally rearward direction. A steering nozzle is positioned rearwardly of the discharge nozzle and pivots about a generally vertical axis. A water diverter bucket assembly is mounted near the steering nozzle and is movable between an opened position and a closed position in which the bucket assembly at least partially redirects the water jet. The bucket assembly comprises a pair of bucket members positioned on opposing sides of the steering nozzle and being pivotal about a substantially vertical axis. Each bucket member comprises a main body portion and a flap member.
For purposes of summarizing the invention, certain aspects, advantages and novel features of the invention have been described herein above. Of course, it is to be understood that not necessarily all advantages disclosed or taught herein may be achieved in accordance with any particular embodiment of the invention. Thus, the invention may be embodied or carried out in a manner that achieves or optimizes one advantage or group of advantages as disclosed or taught herein without necessarily achieving other advantages as may be disclosed, taught or suggested herein.
All of these aspects are intended to be within the scope of the invention herein disclosed. These aspects of the invention, as well as others, will become readily apparent to those skilled in the art from the following detailed description of the preferred embodiments having reference to the attached figures, the invention not being limited to any particular preferred embodiment(s) disclosed.